This invention relates to comminuters for pulverizing solid material and, more particularly relates to an improved spring-loaded tooth for mounting in the comminuter rolls.
Comminuters can be used to pulverize a wide array of solid materials. A typical comminuter using pulverizing rollers is shown in U.S. Pat. No. 4,366,928, issued Jan. 4, 1983, and U.S. Pat. No. 4,477,028, issued Oct. 16, 1984, to John H. Hughes. In both these prior art comminuters the rollers are arranged in an upright position and form a comminuting chamber. The roller arrangement is mounted within a housing of some type that surrounds the array of rollers. The material to be broken down is fed into the top of the comminuting chamber and driven orbitally at a speed sufficient to be forced against the comminuting rollers. Puncturing elements, or teeth, are present on the external surfaces of the rollers to break the material into smaller pieces by both an abrading and puncturing action. The pieces then fall to the bottom of the chamber and exit the chamber through some screening and exit arrangement formed at the bottom of the comminuting chamber. Typically, the exit from the comminuting chamber is formed around the outer perimeter of the base of the housing.
In earlier comminuters the teeth on the rollers were either formed directly as a part of the roller or were welded to the roller so that when the teeth dulled and needed to be repaired or replaced the entire roller had to be removed from the comminuter and either a new roller or refurbished roller put in its place. In another embodiment of a comminuter, holes can be drilled in the comminuting rolls to accommodate individually mounted teeth. Typically, the hole is threaded or the hole is sleeved with a threaded insert. The tooth can be mounted on a threaded stud that cooperatively engages the threaded hole in the roll. While these individually mounted teeth are arguably an improvement over the earlier comminuter rolls, removal and replacement of the teeth still involves unthreading the teeth from the roll, which is a time-consuming job, considering the number of rolls and number of teeth per roll in a large comminuter. Also, the threaded teeth are more costly to produce, as are the threaded holes in the roll. Finally, the comminuter rolls are subject to a great amount of abuse since many types of material, including metals and stone, are crushed by the comminuter and it would be likely for threads to be damaged in the holes for accepting the teeth or the teeth to be broken off of the threaded studs, making removal and replacement more difficult.
It is, therefore an object of the present invention to provide a spring-loaded tooth for a comminuter roll that is easy to install and to remove and that is relatively simple to produce.